PHOTOELECTRON-SPECTROSCOPY OF THE ANNEALED AND DEUTERIUM-EXPOSED NATURAL DIAMOND (100) SURFACE

Hydrogen, playing a crucial role in diamond film growth, can be desorb ed from the diamond (100) surface simply by annealing at elevated temp eratures. The effect of such a treatment on the electronic bulk and su rface properties of diamond (100) at different temperatures has been i nvestigated by valence band and core level photoelectron spectroscopy. On annealing, additional electronic states appear in the range from 2 .5 to 0.5 eV binding energy below the Fermi level. The intensity of th ose states show an angular dependency. Exposure of the annealed surfac es to atomic deuterium reverses the effect. The data are discussed in the view of models for surface reconstruction. From a thorough compari son of the observed changes in the photoelectron spectra upon annealin g with graphite related features we can clearly exclude surface graphi tization of the diamond sample in our experiments.